One embodiment according to the present specification relates to a technique for transmitting a long training field (LTF) signal in a wireless LAN (WLAN) system. The LTF signal may comprise an LTF sequence transmitted on the basis of a plurality of subcarriers. For example, a minimum subcarrier index of a plurality of subcarriers may be set to −28, and a maximum subcarrier index of the plurality of subcarriers may be set to 28. A pilot tone may be inserted/allocated to four subcarriers from among a plurality of subcarriers.